Model Output Discussion 12z 03/04/13

[snowingtequila]

Please refer to my corrrection above

yep sorry we were writing at the same time!

[Timmytour]

No not really as it says the opposite! It suggests that we the chances of us remaining cold next week are higher according to this morning's models

High odds = low probability...low odds ...high probablility. Gibbo stated it awkwardly but correctly.

I guess this undercutting low then, far from bringing the excitement it would have a month ago...is instead taking us on a cooler and wetter path towards something we'd recognise as Spring instead of the steady temperature rise while remaining dry?

[johnholmes]

Better clear this one up. It was written in a hurry and on reading it back it doesn't make much sense. What I meant to say is that there is still a lot of cold around to the North of the UK in the charts for next week and because of that I wouldn't be surprised if it stayed cold for much of next week over the UK, especially the North. Sorry for the confusion.

thanks Gibby-exactly what I thought you meant, thanks for taking the time to explain

[Nick F]

not seen anything since yesterdays 12z gfs.... begining to think the warm up was in the bag, after my earlier scepticism was starting to wane.... then i saw this mornings runs, ... oh dear... forget fi (c t144 onwards), this morning its looking like the block wont give up as easily as been recently progged, and that yet again the 'saviour' system could very well become a slider , tracking into france and leaving us in the bloody cold....

so its pointless looking past monday atm, the cold is in situ and its not going anywhere fast.

This chart may cheer you up Mushy!

A lot of uncertainty over the position of the low from early next week which is linked in to how far south the models dig the trough/jet. Euros dig the trough/jet deeper across W Europe, thus place the low to the SW of the UK at t+144, GFS shallower with the trough and the low to the NW of the UK. So I can see your worries, as when the trough eventually moves east, cold air returns from the north on ECM ... though it could be a temporary return to cold before the jet returns north again ahead of the next Atlantic trough with low pressure system moving in.

Edited April 4, 2013 by Nick F

[West is Best]

06z rolling out and it maintains the huge potential for an undercut snow event of some significance from Sunday onwards. Although the trend may be for warming up the idea that this cold is going to be knocked out in Round 1 is receding fast. In fact, next week is starting to look like the sort of battleground which may produce considerable snow at least for a while in some places.

We ought to remember that it's the breakdown undercuts that are the real harbingers of snow, and with an easterly cold of this potency that can still mean significant snowfall in April.

Edit. No offence, but also in this situation posting charts for 15th April is best seen as light-hearted banter, which I know it is. The models are still not at all clear about the next 5 or 6 days - which is the point you also made anyway Nick

Edited April 4, 2013 by West is Best

[Captain Shortwave]

If anything more energy is going into France now on the GFS

00z

[Tamara]

If we look at the ECM maps at t120 we can see a mixed picture wrt how the low in the atlantic orientates itself. Quite a split overall in terms of whether the low is positively tilted, lifting the cold air NE'wards from the UK - or more negatively tilting and undercutting the cold air that has been in situ for so long. At least to varying degrees.

The latest GFS output is broadly very similar to the ECM operational out to this time, and with the UKMO also taking the more southerly track as well then there is much to be decided yet in terms of where we will be by the early part of next week.

Good evidence has been posted already that illustrates how the polar profile is expected to change as the residual effects of the negative zonal anomalies at the tropospheric surface which have driven the easterly pattern for this remarkable time are replaced by mean westerly winds once again downwelling from the stratosphere as the polar votex regains some last minute strength.

However the exact timing of this remains unclear wrt when the models are trying to suggest it will happen. Based on some of the background factors as described, it could well be that the suggestions of change in pattern we have seen are correct, but, as current modelling uncertainty this minute suggests, it may be a little early and the change may come closer to mid month. Time will tell

Edited April 4, 2013 by Tamara Road

[Summer Sun]

Lovely 00z run from mid month for a time

I not sure where the snowy breakdown could occur next week GFS doesn't show it away from the far north of Scotland

Come mid week we hit a barmy 15c

[-uksnow-]

The amount of spread on the synoptics at t96 of GEFS 06z is ridiculous, alot of options there.

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=96&code=20&mode=0&carte=0

[frosty ground]

Lovely 00z run from mid month for a time

I not sure where the snowy breakdown could occur next week GFS doesn't show it away from the far north of Scotland

Come mid week we hit a barmy 15c

Those charts are 10 days....... Not really worth posting considering the same charts have been shown for the last month. Still we can still hope for some warmer weather!

[Captain Shortwave]

Might sound controversial but the 06z output should be binned. Complete ensemble mess at T96

[weatherguy]

Looks like our old friend shannon is back to say hello in the 06z run

[Nick F]

06z GFS still not keen on sinking the jet and the Atlantic lows as far south as the Euros and still has still has a warm southerly come mid-month with temps hiting 20C!

[Summer Sun]

The ECM Birmingham ensemble continues its steady rise over the next 2 weeks

The minimum temperature also begins to rise after holding steady to the 6th

Precipitation shows a 3 day spike next week 9th, 10th, 11th before it begins to fall to average and then below average again

[Milhouse]

Indicatons are there for a considerable rise in pressure over Europe over the next 8 days with low pressure that has been channelling cold southwards finally giving way to high pressure building warmth northwards. How close this warmth gets to the UK is still uncertain.

[mushymanrob]

This chart may cheer you up Mushy!

well it doesnt!

not until its within a reliable timeframe ! :lol:

[The PIT]

well it doesnt!

not until its within a reliable timeframe !

What about this one from the ECM

[Summer Sun]

The bulk of the GFS ensembles are at the right side of the average line from the 9th onwards for London and Manchester

More scatter on the Aberdeen ensemble

[Average Joe]

http://blogs.agu.org/wildwildscience/2013/04/04/nasa-satellite-measures-the-effects-of-greenland-block-that-stopped-spring/

I have no idea which thread to post this in, so I'll let those in charge move it around to where their hearts content, but I thought some of the more scientifically minded may find this article of interest.

[-uksnow-]

Subtle differences even by T60 on the GFS - as has been happening with all runs, more energy is being sent further south.

Stronger (more robust) heights/thickenss built ahead of the low.

06z

[Summer Sun]

The low to the SW during the early hours of Monday is 5mb less deep when compared to the 06z run other than that no major changes so far

Rain for the south west and western Ireland dry light snow possible for the northern and Scottish hills

Does anyone know whats happened to the UKMO updates? Meteociel is stuck on yesterdays 12z and wetterzentral has updates at 12z, 00z, 06z and 18z depending what time you click on

Edited April 4, 2013 by Gavin.

[Paul]

Does anyone know whats happened to the UKMO updates? Meteociel is stuck on yesterdays 12z and wetterzentral has updates at 12z, 00z, 06z and 18z depending what time you click on

They're fine here

http://www.netweather.tv/index.cgi?action=meto;sess=

[-uksnow-]

Does anyone know whats happened to the UKMO updates? Meteociel is stuck on yesterdays 12z and wetterzentral has updates at 12z, 00z, 06z and 18z depending what time you click on

Wetterzentrale hasn't updated at all, the 12z, 00z etc is simply the time of day your clicking on from the 00z model run as UKMO only runs 00z and 12z model!

[Summer Sun]

Less cold air moving in on Wednesday

Edited April 4, 2013 by Gavin.

[Captain Shortwave]

GFS

GEM

I have to admit I do find it funny how the GFS manages to wrestle the jet profile to the SW/NE tilts it's gagging for each time, even when energy has gone under height to the north, it simply pulls it all back and sends it North East

GEM following the EUros output this morning. Who knows what's happened to the UKMO,

Edit actually GEM is going on it's own merry way now building a ridge in the North sea, this holds to T144, dry and cold from start to finish.

Edited April 4, 2013 by Captain shortwave